Conductive ink and tabulator system



Patented June 22,1937

UNITED STATES CONDUCTIVE INK AND TABULATOR SYSTEM William W. Lasker,Jr., Brooklyn, N. Y.

No Drawing. Application April 21, 1934, Serial p No. 721,715

1 .Claim.

This invention relates to tabulating card systems, and particularly tothe cards'useable therein, and to the tabulating machinery, and furtherto methods-of making conductive markings upon tabulator cards for therecording of data thereon and for the cooperation thereof with atabulator mechanism. 5

For tabulating purposes, it has been customary to use individual datacards upon which the several items of data from a given transaction arerecorded. The recording has previously been done customarily by thepunching of holes at designated or significant positions on the card toindicate the desired data. These .cards have customarily been sensedbythe passage of mechanical members through the perforations to producemechanical displacements thereof, which are utilized directly for thetabulation of .theindicated data, or the movements of the mechanicalmembers are utilized to complete electric circuits in which the currentflow enenergizes magnets to produce the desired tabulating of theindicated data.

The present invention provides a data card system including a specialmarking ink, which is electrically conductive, which is applicable tothe card at significant or designated points on the card to indicate thedesired data. The spots are adapted to be sensed by electrical members,

which permit current to flow when a significant ink spot appears in agiven position on the card, but which prevent the flow of current whenthe ink spot is absent.

An object of this invention is to apply an electrically conductive inkto a significant spot upon a data card and to utilize the said inkedspot to close an electric circuit for the production of a desiredresult, such as tabulating or sorting, etc.

Another object of this invention is to produce electrically conductiveinks and more particularly those which when properly dispersed andimpregnated into a suitable ribbon, are capable of being transferredfrom the ribbon to a record card or the like, by pressure, or by a blowexerted by a plunger or type under manual or automatic control, toproduce on the card or record a deposit or mark, which is electricallyconductive.

A further object is to cause the deposit to be so made on the card as todry readily, and, after drying, smudge or blur as little as possiblewhen rubbed.

Still another object of this invention is to produce a conductive markon a. record card by means of chemical action between sizing .on a cardand a suitable substance or vehicle carried by a ribbon or other means.In this instance, it is desirable that the chemical action bepractically instantaneous and the deposit permanent, also" that therecord itself should not be so affected by time or storage as to resultin any physical deterioration.

Another object of the invention is to prepare conductive inks, which maybe applied by a printing press or other well known means whereby the inkneed not be conveyed by a ribbon. In this case, the ink need not possessthe characteristics required for recuperation.

The device of the invention thus provides materials and processes formaking tabulator cards in which the significant record is produced by anink spot having electrically conductive properties; by means of ribbonmaterials, which are recuperative, which produce a permanent record, andare not subject to physical deterioration.

Other objects and details of the invention will be apparent from thefollowing description:

In order that more than one mark be made from the same portion of theribbon, the ink on the ribbon must be recuperative. In other words, theink must remain permanently fluid in the ribbon. The ribbon employedshould preferably be of high count, that is, of very fine weave, so thatbest recuperation is obtained.

Re-inking can be resorted to where a nonrecuperative ink is used on aribbon.

Conductive inks may be of two general types, one which is absorbed by orpenetrated into the card, and the other which adheres to the surfaceonly of the card. A combination of these two types is also possible.

Conductive inks, consisting of graphite or other metals in colloidalformin a volatile liquid, are well known, and, when applied to a surface,the volatile liquid evaporates, leaving a deposit which is homogeneousand electrically conductive. Such inks, however, cannot be used toaccomplish the purpose of this invention.

To produce an ink of the character described herein, which will beabsorbed by paper, it is preferable to use as the conductive medium,deflocculated Acheson graphite, mixed to colloidal fineness, with aproper oil vehicle, such as castor oil, and, if desired, an indulinebase and oleic acid. This mixture is thoroughly ground in a high speedcolloid mill, and then applied to a ribbon such as is used in atypewriter. The mark produced from this ribbon is conductive, but it isfound that superior results are obtained by mixing in, mechanically, acoarser grade of should be relied upon for recuperation, and the largerparticles forfilling in the interstices formed by the oil filmsurrounding each particle triethanolamine oleate.

capillary action takes place.

of colloidal graphite.

Sodium silicate may be used as a dispersing medium, in which is grounddeflocculated Acheson graphite, the "whole of which is then made up in aviscous mineral oil vehicle. The purpose of the mineral oil is toproduce a certain stickiness,

while the sodium silicate has the property of honey-combing the oilvehicle, thus increasing the conductivity.

, A conductive mark may also be produced by' thoroughly mixing a lightoil with an equal weight of triethanolamine and one-half this weight ofintroduced as a dispersing medium and for also causing the oil topenetrate more readily. A conductive ink may be preparedby mixingAcheson graphiteand triethan'olamine in a colloid mill. The mark,produced from, a ribbon saturated with this ink, adheres to the surfaceof the paper and is electrically conductive. The conductivity of thismark can be increased by adding mercury and a trace of rosin. Thetrie'thanolamine is used in maintaining conductivity and recuperation,as it is non-drying and hydroscopic.

, When graphite of ultra-microscopic particle size isused as theconductive medium, it is found that, when the ribbon isimpregnated withthe ink, This property is especially valuable where the ink is used on astamp pad and also for placing deposits on a fabricor paper tape so thatthe markings maybe sensed from either or both sides of the tape.

It will be apparent to those familiar with inks I that varioussubstitutes may be employed for the graphite, such as carbon black,metallic colloids,

metallic soaps, etc., and that various combinations may be made oftheformulae described herein. Also various, oils may be used as olive oil,petroleum, neats-foot oil, petrolatum, petroleum'jelly, etc.

The conductive inks may also be made in the following manner: v v

By preparing a'metallic colloid in oil by the electricarc method.

By incorporating gelatine-water-glycerine colloid in alight mineral oil,in which graphite is incorporated by grinding.

By mixing electrically produced copper colloid in light mineral .oil,partially dissolved in blue tungstate toner with graphite ground in,

This triethanolamine is By creating chemical action between suitablesizing material on the card and the proper reactive means carried by aribbon or other means, a conductive mark will result when the reactivemeans is transferred from the ribbon to the card by suitable types. Thisresult is accomplished by coating the card or record surface with grayzinc gelatine mixture. By bringing this surface in contact with a ribbonhaving impregnated thereon a solution of tin chloride, dispersed inheavy mineral oil, acidified with hydrochloric acid, a deposit ofmetallic tin is made on the card.

A silk ribbon is used as it is not affected by the acid. Other meansbesides the ribbon may be,

used to introduce the reactive'substance to the card surface.

This invention thus provides a tabulator card and ink material, which,in combination, produce upon the card a mark which is significant forthe recording of items of information ,or data. The card, so marked,thus becomes available for use in a mechanical tabulator, or sorter, orother mechanical sensing device, in cooperation with electrode memberstherein. The ink markand.v

fore, desired that only such limitations shall be imposed upon theappended claim as are stated therein or required by the prior art,

The invention claimed is: The method of producing a conductive mark upona tabulator card comprising the steps of applying a non-conductivecoating to the surface of the said card and applying thereto a spot ofsubstances adapted to react therewith andproduce a conducting spot uponthe card, the said coating'comprising zinc dust as a reducing materialand gelatine as an adhesive, the spot producing material comprising asoluble salt of a conducting metal dispersed in a non-volatile oilmedium.

' WILLIAM W. LASKER, JR.

